Patent GB-835472-A (GB)
Title: Improvements in or relating to crushers
IPC: B02C2/04
Filed: 1958-10-08
Abstract: 835,472. Gyratory crushers. NORDBERG MANUFACTURING CO. Oct. 8, 1958 [Oct. 16, 1957; Sept. 8, 1958], No. 32111/58. Class 59 The normally stationary member or bowl 18 of a gyratory crusher is made vertically adjustable by rotation within a threaded tilting ring 13 and is held against rotation after adjustment by applying an upward thrust to the bowl through a number of thrust mechanisms 40 spaced around the frame 9. Each thrust mechanism comprises a rocker 42 which bears on the ring 13, and is associated with a spring cluster 29 and is fulcrumed at 54a so that the inner end of the rocker 56a engages the flange of a lock ring 58a to provide an upward thrust on the ring. The ring 58a is screwed to the bowl 18 and to an upward extension 66a of the bowl to which the extension is welded, or it may be formed integrally therewith. Over the bowl extension 66a is fitted a dust-excluding element cap 72 having vertical internal ribs 76 which engage with notches 78 formed in the flanged top edge of the extension 66a. The cap 72 has a flanged lower edge 80 having notches 96 engageable by the inner ends 94 of releasable locking members 86, Fig. 3. The upward thrust on the bowl 18 through the lockring 58a ensures that any slackness in the screw threads 13a, 19 and 65a is taken up so that impacts from crushing will be transmitted directly to the tilting ring 13. The spring clusters 29 serve to provide this upward thrust, to hold the tilting ring in contact with the crusher frame 9 at a predetermined pressure, and to retain the locking member 86 in their engaged positions; during assembly clearances are provided below the washers 64a and 111 to allow the springs to exert a downward pull on bolts 36, 46 and 98. A number of hydraulic jacks 102 are mounted on platforms 104 on the main frame 9, one jack below each spring cluster so that it may engage a plate 38 whereby the spring tension on the bolts 36, 46 and 98 is relieved, thus releasing the bowl 18 for adjustment. The jacks below the locking members 86 are each provided with a stop which, on further extension of the jacks, engage a sliding bar 106 which lifts the bolt 98 and the inner end 94 of the locking member 86 clear of the notch 96 in the flange of the adjustment cap 72. The jacks 102 are simultaneously operated by a hydraulic system which includes check valves so that, in the event of a failure of pressure when in the extended position, fluid is trapped in the jacks to hold the bowl 18 in the raised position. Rotation of the bowl 18 when freed for adjustment is effected by one or more hydraulic rams 118, Fig. 1, of which one element is pivotally attached to a lug 119 on the crusher frame whilst the other engages a projection 164 formed on the edge of a ring 162 attached to the wall of the adjustment cap 72. A spring 156 maintains the free end of the jack 118 in contact with a projection 164 until the end of its stroke when a manually operated reversing control retracts the moving member so that its free end engages with another projection . on the ring 162. The ends of the spring 156 are attached to the upper ends of studs mounted one on the jack and one on the ring 13 above the level of the jack which may be moving through a dead-centre position to operate tangentially to the ring 162 in either direction. During rotation of the bowl 18 the lock-ring 58a is prevented from turning by welded on blocks 168 located between the cheeks 88 which flank the locking members 86.